The company is slashing approximately 15 per cent of its workforce and closing five facilities in North America, including its 55-year-old assembly plant in Oshawa. The move is expected to leave approximately 2,500 union workers without jobs in Oshawa once production ceases.

Here’s how General Motors’ tenure in Oshawa unfolded over its more than 100-year history.

1907-1908 – Carmaking comes to Oshawa

Oshawa businessman Robert McLaughlin and his sons, Sam and George, decide to overhaul their carriage-making facility so they could start making their own automobiles.

The company starts producing McLaughlin Buicks before adding Chevrolets and Pontiacs to its lineup, as part of a business relationship with General Motors in the United States.

WATCH: ‘They’re not closing our damn plant without one hell of a fight’ says union leader

1918 – General Motors Canada is born

General Motors buys the McLaughlins’ car-making business and transforms it into GM Canada. Sam McLaughlin is named its first president, with his brother George serving as vice-president.

The company grows rapidly over the following two decades. Oshawa also expands and becomes a city in 1924, with 15,545 residents.

2005 – GM decides to shut down McLaughlin’s plant

General Motors announces it will close down 12 factories in North America, including the secondary Oshawa plant where Sam McLaughlin founded his Canadian car-making business. The plant closure eliminates 3,750 jobs.

WATCH: Shifting attitudes among drivers and auto industry

2008 – Strike and a closure announcement

General Motors strikes a tentative deal with the Canadian automotive workers on May 15, 2008, to continue production in Oshawa. Three weeks later, the company announces it will close its pickup truck plant, outraging the union workers.

June 2009 – Fast cars and billion-dollar bailouts

GM files for bankruptcy protection. Canada, the U.S. and Ontario give GM roughly US$60 billion in loans to help it continue production through the Great Recession, in exchange for shares in the company. Those shares were all sold off by 2015.

GM announces it will resurrect its muscle-car line, the Chevrolet Camaro, with production to take place in Oshawa.

Mary Barra, GM’s chairman and CEO, says the move is meant to “stay in front of changing market conditions and customer preferences to position our company for long-term success.”

Federal, provincial and local politicians widely condemn the move.

WATCH: Politicians react to GM’s departure from Oshawa

“GM workers have been part of the heart and soul of Oshawa for generations – and we’ll do everything we can to help the families affected by this news get back on their feet,” Prime Minister Justin Trudeau tweeted.

GM workers have been part of the heart and soul of Oshawa for generations – and we’ll do everything we can to help the families affected by this news get back on their feet. Yesterday, I spoke with @GM’s Mary Barra to express my deep disappointment in the closure.